A gas pump is used in semiconductor manufacturing for extracting gases from the chamber. In some cases, the gas pump is a turbomolecular pump. The gases travel through multiple stages in the gas pump, and as the gases travel down through the gas pump, the gas pressure changes, which may cause the gases to solidify and create residues on the inside of the gas pump. The residues may clog the gas pump, thereby limiting or stopping the gas pump from proper operation.
In some cases, the outside of the gas pump is heated to raise the temperature of the gas pump to try to prevent the gases going through the gas pump from developing deposition byproducts. However, the amount of heating that may be applied to the gas pump is limited due to various factors, such as, rotor material, rotational speed, and temperature. For example, some aluminum rotors may not be operated above 130° C.
In many cases, it is difficult to determine if the gas pump is failing because it is not easy to access and examine the inside of the gas pump for residue. It has been observed that the operation of the chamber often degrades and/or malfunctions over time. The degradation sometimes can be resolved by changing the gas pump, indicating that gas pump malfunction is the root cause of the degradation. One of the main causes of malfunction is the deposition of materials inside the rotor and the inside walls of the gas pump.
The background description provided herein is for the purposes of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.